Termination Resistor; Power Jumper Settings - MSA FieldServer ProtoCarrier FPC-C34 Startup Manual

3.3.2 Termination Resistor

Termination resistors are also used to reduce noise. These pull the two lines of an idle bus together. However, they would
override the effect of any bias resistors, if connected.

3.3.3 Power Jumper Settings

The ProtoCarrier power jumper is set to position A by default but can be changed to position B for other power supply
requirements.
Position A: The gateway makes use of a full-wave rectifying bridge. Can be used for 12-24 VAC input or
9–30 VDC input. At 9 VDC this becomes marginal.
Position B: The gateway makes use of a half-wave rectifying bridge. Best position for grounded AC transformers and for
using DC voltage down to 9VDC.
11 ProtoCarrier Start-up Guide